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The genus Scopulariopsis contains over 30 species of mitosporic moulds, which although usually saprophytic may also act as opportunistic pathogens in humans. They have mainly been associated with onychomycosis, and only sporadically reported as a cause of deep tissue infections or systemic disease. Identification of Scopulariopsis species still largely relies on phenotype-based methods. There is a need for a molecular diagnostic approach, that would allow to reliably discriminate between different Scopulariopsis species. The aim of this study was to apply sequence analysis of partial 28S rRNA gene for species identification of Scopulariopsis clinical isolates. Although the method employed did reveal some genetic polymorphism among Scopulariopsis isolates tested, it was not enough for species delineation. For this to be achieved, other genetic loci, within and beyond the rDNA operon, need to be investigated.
In some legal proceedings, the species identification of animal on the basis of fragments of biological material is extremely difficult. This applies both to closely-related and to distant species characterized by similar morphological features. In such circumstances, methods of molecular biology are used, whose evidential value is definitely not in doubt. Histopathological scraps may also have to be used for identifying tests. The aim of the present study was to verify the possibility of using DNA analysis in determining the species of animals on the basis of biological material contained in archival histopathological samples. The examined material consisted of twenty-eight histopathological preparations stained with hematoxylin and eosin. The samples had been prepared from the liver, kidney, spleen, and skeletal muscles. Their age varied from one to seventeen years. Specimens (from twelve species) were identified by inputting sequences in the Barcode of Life Database species identification tool on the basis of the similarity percentage figure from the BOLD report. It was found that genetic tests can effectively identify animal species through the analysis of biological material from histopathological samples.
Molecular phylogeny of crocidurine shrews (Insectivora, Soricidae) in northeastern Asia was investigated to confirm the taxonomic status of unidentified specimens of Crocidura from Cheju Island, South Korea. Phylogenetic trees were constructed by neighbor-joining (NJ) and maximum likelihood (ML) methods, based on mitochondrial cytochrome b gene sequences (402 base pairs) of 37 individuals of seven crocidurine species and three unidentified specimens from 31 localities mainly in northeastern Asia. Phylogenetic position of the three unidentified specimens from Cheju Island were compared with those of Suncus murinus, C. attenuata, C. dsinezumi, C. lasiura, C. sibirica, C. suaveolens, and C. watasei. Both in NJ and ML trees, the three unidentified specimens were included in the cluster of C. dsinezumi and were obviously different from C. suaveolens on Cheju Island. Thus, the present investigation demonstrated that both C. suaveolens and C. dsinezumi exist on Cheju Island.
The aim of this study was molecular identification of S. aureus strains isolated from mastitic milk samples and establishing the genetic relationship between strains isolated from cows belonging to the same herd. In all 43 isolated strains the gap gene (930 bp) was amplified, which enabled their affiliation to the Staphylococcus genus to be established. PCR-RFLP with AluI endonuclease of the gap gene as well as nuc (450 bp) and coa (1130 bp) gene amplification allowed precise S. aureus species identification. One hundred percent of the genetic relationship between strains was established via RAPD-PCR and coa-typing.
DNA barcoding is a practical tool for species identification, when morphological classification of an organism is difficult. Herein we describe the utilisation of this technique in a case of ophthalmomyiasis interna. A 12-year-old boy was infested during a summer holiday in northern Norway, while visiting an area populated with reindeer. Following medical examination, a Diptera larva was surgically removed from the boy’s eye and tentatively identified from its morphological traits as Hypoderma tarandi (L.) (Diptera: Oestridae). Ultimately, DNA barcoding confirmed this impression. The larval cytochrome c oxidase subunit 1 (COI) DNA sequence was matched with both profiles of five adult H. tarandi from the same region where the boy was infested, and other established profiles of H. tarandi in the Barcode of Life Data Systems (BOLD) identification engine.
DNA-based identification of species for phylogenetic analysis as well as forensic identification is widely being carried out with the help of polymerase chain reaction (PCR). In this study, a successful effort has been made to identify 5 species of Indian freshwater turtles, including 3 hard-shell turtles (Geoemydidae), i.e. Kachuga dhongoka, K. kachuga and Geoclemys hamiltoni, and 2 species of soft-shell turtles (Trionychidae), i.e. Aspideretes gangeticus and Lissemys punctata punctata, by using a well-optimized PCR-RFLP method. The analysis of nucleotide sequence variations in the PCR-amplified mitochondrial cyt-b genes (encoding cytochrome b) from the 5 species revealed its usefulness in the taxonomic differentiation of these species. On the basis of cyt-b sequence data and the PCR-RFLP pattern, a phylogeny was developed to resolve the genetic relationships between these species, living in the same habitat type. In comparison, the PCR-RFLP of mitochondrial 16S rDNA genes appeared less decisive in analysing phylogenetic relationships or even in species differentiation. Further, the molecular method (PCR-RFLP) developed here is simple, rapid, reliable and reproducible; hence it can be routinely applied for species identification, essential for conservation and management of endangered chelonian species.
The aim of the study was to apply a polymerase chain reaction (PCR) to confirm a presence of hake (genus Merluccius) in a pool of processed seafood samples. A short fragment of the cytb in the mitochondrial control region was amplified. The hake- specific PCR product, due to its limited size, was obtained in a variety of tissue samples. A different level of DNA concentration and degradation, including processed food products, was observed. A total of 64 products were tested and despite their labels, 13 of them were proved to contain no hake. Our protocol for hake identification is faster and more convenient than currently employed methods and may facilitate the identification of fish species.
It has recently been suggested that goitered gazelles (Gazella subgutturosa and Gazella marica) have paraphyletic maternal origin, and that the mitochondrial cytochrome b gene fragment can be used for species identification prior to reintroduction of the gazelles. Although there is a large geographic area where the gazelles have intermediate morphology, previous researchers have not inferred any signs of mitochondrial haplotype introgression, and it is thought that the introgression, if it exists, is male-biased. We studied mitochondrial haplotypes of morphologically typical G. subgutturosa from two geographic locations. Goitered gazelles from eastern Turkey, morphologically identical to G. subgutturosa, had haplotypes identical to G. marica. This finding confirms ongoing maternal gene introgression from G. marica to G. subgutturosa. Our suggestion is that there is a natural gene flow between these two nominal species, and morphological characters together with recombinant genetic markers rather than mitochondrial DNA should be used to differentiate among individuals from areas close to the contact zone.
A duplex-PCR method, with 2 pairs of primers recognizing sequences of mitochondrial D-loop region, was developed to identify cows’ milk in the milk of goats. The PCR was shown to be specifi c and sensitive, enabling the detection of less than 1% of cows’ milk added to the milk of goats. Simultaneous use of a primer pair for goats’ and cows’ mitochondrial DNA fragment prevented false negative results. The method was applied to track the presence of cow DNA in goat milk available on the Polish market. A total of 54 milk samples from 3 Polish (34) and one foreign producer (20) were examined. In 33 samples, cow DNA was detected, while 21 samples, including all of the 20 samples from foreign producers, produced the goat-specific product only.
Electrophoretic methods can be used to identify meat of various animal species. The protein electrophoresis, especially the IEF of the sarcoplasmic proteins, is a wellestablished technique for species identification of raw fish and is used in the control of seafood authenticity. However, in the case of the analysis of heat-processed fish, the method is applicable only to those species which possess characteristic patterns of the heat-stable parvalbumins. Heat-denatured fish muscle proteins may be solubilised by urea or sodium dodecylsulfate (SDS) and separated by urea-IEF or SDS-PAGE, respectively. The comparison of these two methods allowed to conclude that, basically, each of them can be used for species identification of heated fishery products. However, extensively washed products may be preferentially analysed by the SDS-PAGE, because most of the parvalbumins are washed out leaving mainly myosins. On the other hand, the IEF method may be preferred for the differentiation of closely related species rich in parvalbumins isoforms. It is evident from the literature data that species-specific protein separations yield proteins of low molecular weight made up of three light chains of myosin (14-23 kDa), troponin (19-30 kDa) and parvalbumin (about 12 kDa). Investigations showed that the SDS-PAGE method can be used to identify meats of: cattle, sheep, lambs, goats, red deer and rabbits. The technique allowed researchers to identify the following myofibrillar and sarcoplasmic muscle proteins: myosin and actin, -actinin, tropomyosin, troponin. SDS-PAGE allowed the identification of myofibrillar proteins taking into account their molecular weights which was not possible with the assistance of the PAGIF because too many protein bands were obtained. It was possible to obtain differences in the separation of proteins characteristic for certain species, e.g. beef, resulting from the presence of single myofibrillar proteins
A rapid PCR-RFLP analysis was optimized to identify the presence of 3 closely related gadoid fish species: Alaska pollack Theragra chalcogramma, Pacific cod Gadus macrocephalus and Atlantic cod Gadus morhua in commercial seafood products. Gadoid universal primers were designed for PCR amplification of a 558-bp fragment encoding the mitochondrial cytochrome b gene. Without purification of the PCR products, double digestion with Eco32l and Eco1051 restriction enzymes generated reproducible species-specific restriction patterns visualizing 3 fragments (106 bp, 161 bp and 291 bp) in Alaska pollack and 2 fragments (106 bp and 452 bp) in Pacific cod, whereas no cleavage was observed in Atlantic cod. This PCR-RFLP analysis is simple, rapid and reliable, and therefore can be routinely applied to discover fraudulent substitution among 3 economically important gadoid species in commercial seafood products.
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